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BIG PICTURE: Saturday 1.6.18
NPAC: The consolidated powerful Jet Pattern continues fairly low off Japan with 190-200+kts pockets ranging ~30-40n Lat. or 600-1200 miles North of our Latitude. Weaker 140kt winds spread out to beyond our Lat. to 150W with High pressure to our N all the way to the mainland early in the 7 day outlook. There’s plenty troughs in the Jet allowing for counterclockwise circulation down at the surface to spin off some nice storms for the long haul.
By Tuesday there’s a split Jet to our NW thanks to a High pressure there, plus by Wednesday complex troughs help shape some more large areas of action/fetches off Japan again.
The Jet re-strengthens up to 220kt pockets supporting a large circulation which spins off a large storm Wed-Friday with a captured fetch and some 40-50’ seas as it crosses the dateline only 1200 miles away! By Thursday the low is weak, plus a good portion of the energy passes to our NE. But some of the fetch points right to us getting very close thanks to the Jets nose dipping toward Hawaii. The sheer size/pwr of the fetch plus plenty sideband swell means GIANT XXL surf this coming weekend. Read Next #2 below.
Recent-Current: We’ve had an excellent run of 14-16 sec WNW-NW surf this past week. Pretty much the best so far, this season thanks to decent size and clean offshore East trades. The source was pushed out end of 2017 from Japan. Currently, the next one comes from a Low off Japan Jan 2nd with the occluding Low’s wide fetch garnering plenty West 280-320 over the course of the slow track. The swell should hit near 7 or 8’ late Saturday for top spots/moments and last into Sunday with up to fresh paced ENE trades. Long periods hit last night and will average 16sec.
Next: This Saturday- Sunday, a new eastbound Low to spawn off Japan once again; it fattens up but the track veers NNE into Monday. Still a wide fetch of 35-45kts sets up some 30’ seas to our NW near the dateline. Watch for long period forerunners Tuesday the 9th with NW surf ramping to 8-10+’ at 15 sec Wednesday 1/10 holding near that size into Thursday dawn as it slowly fades.
Next long range: A powerful Low is on the charts off the Kuril Islands by this Wednesday-Thursday the 10th and 11th. The track is East but due to the powerful Jet nosing close and bending toward Hawaii this storm gets a captured fetch just 1000 miles away and some huge 40-50’ seas our side of the dateline. It’s still early for specifics or much confidence but ww3 wants GIANT NW surf from this ‘one-two punch’ fetch. The first NW pulse peaks Friday with over 15′ surf at 16 sec. (over 25′ crest-trough) and then if the storm gets as close as models have today Saturday the 6th, Saturday the 13th could potential see GIANT 20-30′ at 18 seconds! Models even have deep ocean swells 16-18’! ‘IF’ this model fantasy actually plays out, it would mean over 25-35’ surf and likely the biggest episode of the season. But, models usually run hot (overcall) this far out; plus, this system may end up sending far more to our NE than models predict at this stage. We’ll keep an eagle eye on it.
The Jetstream is pretty much MIA in the prime zone for Hawaii for much of the current 7 day outlook. But, late in the period there’s a North flow. It’s all High pressure until Thursday the 11th when the weak 120kt southern branch tries to bend our way. The Low which spawns within it’s energy is too weak to make it all the way to Hawaii.
By Friday the 12th a new more powerful 160kt Jet flows right up a few hundred miles off the east coast of New Zealand. The Low in this flow does have enough but nothing like a summer event. Read ‘Last’ event below.
Recent/current: Surf’s been tiny but there’s been small SW Taz and SSW sources off NZL from over a weeks ago keeping it at least rideable.
Next: There’s a tiny Low with seas up to 28’ off the New Z coast from Friday-Sunday the 5-7th. We should get some waist high waves at 15 sec. SSW around Saturday the 13th. NW wrap may be much bigger.
Last: As stated above, the meridional Jet helps spawn a Low far off NZL with a NNE track Fri-Sat the 12-13th. Add the typical 7-day journey and we could get some waist high waves Friday-Sat the 19-20th.
Currently: Surf’s risen and up to 3’ plus on ENE trade swell from upstream trades and locally fresh winds with a decline after some reinforcement Tuesday. There should be minor declining variation Wed-the weekend of the 13th.
Tropics: nothing for the next couple days.
See Chart Below for the ‘Travel Time’ Buoy 51101 to Waimea Buoy
Terms: The split Jetstream is why all the Gulf and Alaskan storms are sending North swells. There’s that strong, persistent blocking ridge west of the dateline bumped the Jet up and over into the Bering Sea most November.
Notes: the spectral density graph in the SNN Buoy Page (link below) shows slivers of forerunners that initial text readings do not ‘show’ till later on written buoy updates. Also, note the vertical graph is not ‘wave height’ rather its a measure of wave energy in hertz (frequency or cylces/sec) for the whole ‘band’ (the distribution of power/period in the total wave energy field/spectrum). For SNN’s Buoys ‘per shore’ arrangement pls GO HERE
Links: Get the latest on the tropics at www.hurricanes.gov
For more on the Westpac Typhoons GO HERE
The Central Pacific Hurricane Center outlook for the 2017 Central Pacific Hurricane Season calls for 5 to 8 tropical cyclones to either develop or cross into the Central Pacific with a 40% chance for an above-normal season, a 40% chance for a normal season, and a 20% chance for a below-normal season. An average season has 4 to 5 tropical cyclones, which include tropical depressions, tropical storms, and hurricanes.
Tropical depression forms when a low-pressure area is accompanied by thunderstorms that produce a circular wind flow with maximum sustained winds below 39 mph. An upgrade to a tropical storm occurs when cyclonic circulation becomes more organized and maximum sustained winds gust between 39 mph and 73 mph. A tropical storm is then upgraded to Category 1 hurricane status as maximum sustained winds increase to between 74 mph and 95 mph. (The highest classification in the scale, Category 5, is reserved for storms with winds exceeding 156 mph).
Tropical cyclones go by many names around the world, and the terminology can get confusing. Once a tropical cyclone strengthens to the point where it has gale-force winds—39 mph or greater—it becomes a tropical storm. A storm that reaches tropical storm strength usually gets its own name to help us quickly identify it in forecasts and warnings. Once a tropical storm begins producing sustained winds of around 75 mph, we call the storm a typhoon in the western Pacific near Asia and a hurricane in the oceans on either side of North America. A “typhoon” and a “hurricane” are the same kind of storm, they just go by different names…it’s only a matter of geography.
NWS criteria for High Surf Advisories (first number) & Warnings (second number).
In coordination with civil defense agencies & water safety organizations in Hawai`i, the NWS uses the criteria below for the issuance of High Surf Advisories & Warnings in coordination with civil defense agencies & water safety organizations in Hawai`i.
All surf height observations & forecasts are for full ‘face’ surf height, or ‘trough to the crest’ of the wave.
Advisory and Warning Criteria Shoreline or Location
North-Facing Shores 15 Feet and 25 Feet
West-Facing Shores – Remaining Islands 12 Feet and 20 Feet
West-Facing Shores – Big Island 8 Feet and 12 Feet
South-Facing Shores 8 Feet and 15 Feet
East-Facing Shores 8 Feet and 15 Feet
‘Travel Time’ Buoy 51101 to Waimea Buoy. Distance: 269 nautical miles (~310 miles). Angle: 307 deg
Shoaling is the effect by which surface waves entering shallower water change in wave height (or grow) due to speed change (or slow down). Wavelength is reduced when going from deeper to shallower. The ‘energy flux’ must remain constant (nature’s liquid law) so the reduction in wave group (transport) speed is compensated by an increase in wave height (and thus wave energy density). Yeah, I know…waves are complex AND amazing.
Refraction is the change in direction of waves that occurs when waves travel from one medium to another or depth change. Refraction is always accompanied by a wavelength & speed change. Diffraction is the bending & spreading of waves around obstacles (‘reefs’ and openings).
High Surf Advisories & Warnings NWS criteria below in coordination with Hawai’i civil defense agencies & water safety organizations.
All surf height observations & forecasts are for the full face surf height, from the trough to the crest of the wave.
|North-Facing Shores||15 Feet||25 Feet|
|West-Facing Shores – Big Island||8 Feet||12 Feet|
|West-Facing Shores – Remaining Islands||12 Feet||20 Feet|
|South-Facing Shores||8 Feet||15 Feet|
|East-Facing Shores||8 Feet||15 Feet|
‘Travel Time’ Buoy 51101 to Waimea Buoy
Distance: 269 nautical miles (~310 miles)
Angle: 307 deg
Wave Wave Wave Depth Wave Direction (deg)———-
Period Length Speed Shallow 295, 305, 315, 325, 335, 345, 355
(s) (ft) (nm/h) (ft) Travel Time (hours)———-
10sec. 512. 15. 256. 17.3, 17.7, 17.6, 16.9, 15.7, 14.0, 11.9
12sec. 737. 18. 369. 14.5, 14.8, 14.6, 14.0, 13.0, 11.6, 9.9
14sec. 1003. 21. 502. 12.4, 12.7, 12.5, 12.0, 11.2, 10.0, 8.5
16sec. 1310. 24. 655. 10.8, ,1 1.1, 11.0, 10.5, 9.8, 8.7, 7.4
18sec. 1658. 27. 829. 9.6, 9.8, 9.8, 9.4, 8.7, 7.8, 6.6
20sec. 2047. 30. 1024. 8.7 8.9 8.8 8.4 7.8 7.0 5.9
22sec. 2477. 33. 1239. 7.9 8.1 8.0 7.7 7.1 6.3 5.4
24sec. 2948. 36. 1474. 7.2 7.4 7.3 7.0 6.5 5.8 4.9
Tropical Storm – winds 39-73 mph (34-63 kt)
Category 1 – winds 74-95 mph (64-82 kt)
Category 2 – winds 96-110 mph (83-95 kt)
Category 3 – winds 111-130 mph (96-113 kt)
Category 4 – winds 131-155 mph (114-135 kt)
Category 5 – winds 156 mph and up (135+ kt)
Please visit the Central Pacific Hurricane Center website at www.weather.gov/cphc for the most recent bulletins.
ENSO (The El Niño-Southern Oscillation) is a single naturally occurring climate phenomenon in three states or phases. These involve fluctuating ocean temperatures in the equatorial Pacific. … When temperatures in the ENSO region of the Pacific are near average it is known as ENSO ‘neutral’, meaning that the oscillation is neither in a warm or cool phase.The two opposite phases, “El Niño”(warmer than average) and “La Niña”(cooler than average) require certain changes in both the ocean and the atmosphere because ENSO is a coupled climate phenomenon. “Neutral” is in the middle of the continuum. The MJO (Madden-Julian Oscillation) is an eastward moving disturbance of clouds, rainfall, winds, and pressure that traverse the planet in the tropics and returns to its initial starting point in 30 to 60 days, on average, unlike ENSO which is stationary. In a nutshell, a more active ENSO means more surf.